ABSTRACT
<p><b>OBJECTIVE</b>To explore the role of Notch signaling in human breast cancers, the expression of Notch1 and its ligand JAG1 in human breast cancers and their relationships with clinical stages of breast cancers were analyzed.</p><p><b>METHODS</b>RT-PCR was used to detect the expression of Notch1 and JAG1 in 62 breast cancer specimens and 22 normal breast tissues at the margin of tumor sections, and the statistical difference of expression rates and standardized coefficient between the two groups were analyzed. To compare the expression intensity of Notch1 and JAG1 at different development stages of the illness and at different stages with or without axillary node metastasis.</p><p><b>RESULTS</b>The expression rate and standardized coefficient of Notch1 in human breast cancers were significantly higher than those of normal breast tissues at the margin of tumor sections. The expression rate of JAG1 in human breast cancers was 15%, while JAG1 was not detected in normal breast tissues at the margin of tumor sections. The standardized coefficient of Notch1 in cases with axillary node metastasis was significantly higher than that in cases without axillary node metastasis. The standardized coefficient of Notch1 at stage I was significantly lower than that at stage II, and stage II was significantly higher than stage III. There was no statistically significant difference between stage I and stage III.</p><p><b>CONCLUSION</b>Notch1 and JAG1 are highly expressed in human breast cancers, indicating that the aberrant expression and activation of Notch1 may be related with tumorigenesis of human breast cancer. Notch1 may play different roles at different developmentl stages of human breast cancer.</p>
Subject(s)
Adult , Aged , Female , Humans , Middle Aged , Breast , Metabolism , Pathology , Breast Neoplasms , Genetics , Pathology , Calcium-Binding Proteins , Genetics , Cell Line, Tumor , Gene Expression Regulation, Neoplastic , Intercellular Signaling Peptides and Proteins , Genetics , Jagged-1 Protein , Lymphatic Metastasis , Membrane Proteins , Genetics , Neoplasm Staging , Receptor, Notch1 , Genetics , Reverse Transcriptase Polymerase Chain Reaction , Serrate-Jagged Proteins , Signal Transduction , GeneticsABSTRACT
<p><b>OBJECTIVE</b>To construct two recombinant plasmids of mdr1 and mcl1 shRNA, and to investigate their reversal effect on drug resistance in K562 adriamycin resistant cell lines (K562/A02).</p><p><b>METHODS</b>Two oligonucleotides of mdr1 and mcl1 gene were designed referring to that of GenBank, double-stranded DNA was derived through annealing, and cloned into pRNAT vector digested by two restricted endoenzymes. K562/A02 cells were transfected with the recombinant plasmids. The mdr1 mRNA expression and its protein product P-glycoprotein (P-gp) were detected by RT-PCR and flow cytometry. The expression of mcl1 gene was detected by RT-PCR. 50% inhibition concentration (IC50) of adriamycin (ADM) on K562/A02 cells was determined by MTT method. Cells apoptosis was analyzed by flow cytometry.</p><p><b>RESULTS</b>Comparing with K562/A02 cells, the shRNA of mdrl or mcl1 gene in vitro can remarkably increase the sensitivity of K562/A02 to adriamycin, down-regulate mdr1 or mcl1 gene expression, increase the K562/A02 cells apoptosis rates induced by adriamycin. Cotransfection of mdrl and mcl1 genes shRNA can also down-regulate the expression of their gene, more remarkably increase the sensitivity and apoptosis of K562/ A02 to adriamycin.</p><p><b>CONCLUSION</b>Transfection of mdrl or mcl1 gene shRNA can promote the sensitivity of K562/A02 to adriamycin and cotransfection of the two shRNA can more remarkably do so. The mel1 gene might be involved in adriamycin resistant in K562/A02 cells.</p>